Evidence for topological superconductivity: Topological edge states in Bi₂Te₃/FeTe heterostructure

Majorana fermions have been predicted to exist at the edge states of a two-dimensional topological superconductor. We fabricated single quintuple layer (QL) Bi₂Te₃/FeTe heterostructure with the step-flow epitaxy method and studied the topological properties of this system by using angle-resolved photoemission spectroscopy and scanning tunneling microscopy/spectroscopy. We observed the coexistence of robust superconductivity and edge states on the single QL Bi₂Te₃ islands which can be potential evidence for topological superconductor.